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United States Patent | 5,311,748 |
Bahel ,   et al. | May 17, 1994 |
Refrigerant is metered through the expansion valve based on compressor discharge temperature and ambient air temperature measurements. The microprocessor-based control system selects the appropriate stepper motor valve setting to achieve optimal performance. The temperature measurements used in the control system are decoupled from fluctuations due to shifting of the refrigerant dry out point. This allows the system to be operated at much lower superheat temperatures than heretofore attained, yielding improved performance and longer component life.
Inventors: | Bahel; Vijay (Sidney, OH); Millet; Hank (Piqua, OH); Hickey; Mickey (Sidney, OH); Pham; Hung (Dayton, OH); Herroon; Gregory P. (Piqua, OH) |
Assignee: | Copeland Corporation (Sidney, OH) |
Appl. No.: | 928892 |
Filed: | August 12, 1992 |
Current U.S. Class: | 62/160; 62/211; 62/223 |
Intern'l Class: | F25B 041/04 |
Field of Search: | 62/160,210,211,212,222,223,224,225,204 |
2060589 | Nov., 1936 | Otto | 62/211. |
2112344 | Mar., 1938 | Otto | 62/211. |
4112703 | Sep., 1978 | Kountz | 62/211. |
4165619 | Aug., 1979 | Girard | 62/99. |
4244182 | Jan., 1981 | Behr | 62/211. |
4333317 | Jun., 1982 | Sawyer | 62/212. |
4448038 | May., 1984 | Barbler | 62/212. |
4467613 | Aug., 1984 | Behr et al. | 62/115. |
4495779 | Jan., 1985 | Tanaka et al. | 62/211. |
4498310 | Feb., 1985 | Imanishi et al. | 62/211. |
4499739 | Feb., 1985 | Matsuoka et al. | 62/212. |
4523435 | Jun., 1985 | Lord | 62/212. |
4523436 | Jun., 1985 | Schedel et al. | 62/222. |
4617804 | Oct., 1986 | Fukushima et al. | 62/212. |
4620424 | Nov., 1986 | Tanaka et al. | 62/222. |
4674292 | Jun., 1987 | Ohya et al. | 62/223. |
4706469 | Nov., 1987 | Oguni et al. | 62/222. |
4745767 | May., 1988 | Ohya et al. | 62/211. |
4768348 | Sep., 1988 | Noguchi | 62/225. |
4807445 | Feb., 1989 | Matsuoka et al. | 62/212. |
4835980 | Jun., 1989 | Oyanagi et al. | 62/212. |
4845956 | Jul., 1989 | Berntsen et al. | 62/225. |
4848099 | Jul., 1989 | Beckey et al. | 62/212. |
4848100 | Jul., 1989 | Barthel et al. | 62/212. |
4893480 | Jan., 1990 | Matsui et al. | 62/225. |
5000009 | Mar., 1991 | Clanin | 62/115. |
5077983 | Jan., 1992 | Dudley | 62/228. |
Foreign Patent Documents | |||
0052957 | Feb., 1990 | JP | 62/223. |
Itoh, H. "Improvement of a Heat Pump Room Air-Conditioner by Use of Pulse-Motor-Driven Expansion Valve," Paper No. 2944, pp. 164-172. |